MasterSeal M 790 designed for waterproofing and protecting concrete | MCT CHEMICALS | MASTER BUILDER SOLUTIONS

FIELD OF APPLICATION
MasterSeal M 790 is used in waterproofing applications where high chemical resistance is essential. Typical applications include:

• Wastewater treatment plants (inflow and outflow areas)
• Sewage effluent pipelines
• Biogas plants
• Secondary containment areas

It can be applied on:

• Horizontal and vertical surfaces
• Internal and external areas, including those exposed to rubber wheel traffic
• Concrete, cementitious mortar, or steel substrates
• Reinforced concrete, offering protection against carbonation, chloride-induced corrosion, and chemical attacks in secondary containment areas of chemical and petrochemical industries.

FEATURES AND BENEFITS

• Easy to apply by roller or trowel
• Provides a continuous, monolithic membrane—no seams, laps, or welds
• Excellent resistance to chemicals, including high concentrations of biogenic sulfuric acid
• Waterproof and resistant to standing water
• Fully bonded to substrates with the appropriate primer
• Moisture-tolerant, can be applied to surfaces with high residual humidity
• High resistance to carbon dioxide diffusion, protecting concrete from rebar corrosion
• Exceptional tear, abrasion, and impact resistance, withstanding mechanical damage
• Flexible and crack-bridging, offering durability with reduced cracking due to embrittlement
• Thermoset properties ensure it doesn’t soften at high temperatures
• Excellent adhesion to various substrates (concrete, steel)
• Weatherproof with proven resistance to thunderstorms, freeze/thaw cycles, and outdoor exposure without additional topcoating
• Solvent-free
• Can be spray-applied using selected 2-component spray machines (consult technical service for details)

APPROVALS AND CERTIFICATES

• Long-term resistance to biogenic sulfuric acid corrosion (Fraunhofer Institute)
• CE Certification according to EN 1504-2
• Chemical resistance according to EN 13529
• Bond strength and blistering resistance when exposed to reverse moisture (DAfStb Repair Guidelines)
• DIBt Approval for use in biogas facilities, tanks, bunker silos, and containment areas for liquid manure and silage storage

APPLICATION METHOD

(a) Surface Preparation
Substrates (new or old) must be structurally sound, dry, clean, and free of laitance, loose particles, oil, grease, rubber skid marks, and paint stains.
For concrete, prepare the surface using shot blasting, high-pressure water jetting, or other suitable methods. Concrete and other cementitious substrates must have a minimum pull-off strength of 1.5 N/mm² (lowest single value 1.0 N/mm²).
For steel, sandblast to a SA 2½ finish before applying MasterSeal M 790. No primer is needed for steel.
The surface temperature must be between +5ºC and +35ºC, and at least 3ºC above the ambient dew point.

(b) Primer Coat
A primer improves adhesion and prevents pinholes or bubbles in the hardened coating. MasterSeal P 770 is the recommended primer. Apply by roller in one layer, using 0.25-0.4 kg/m². Wait at least 5 hours at +20°C before applying MasterSeal M 790. Apply the subsequent coat within 48 hours. If more time elapses, consult a technical representative.

(c) Mixing
MasterSeal M 790 comes in pre-measured kits. Pour the entire contents of Part A into Part B and mix with a low-speed drill (max. 400 rpm) for 90 seconds. Scrape the sides and bottom of the container to ensure complete mixing. Avoid mixing by hand and ensure all mixed material is used immediately.

(d) Application
Apply MasterSeal M 790 with a brush or roller, typically in two layers. The minimum waiting time between coats is 8 hours at +20ºC. Apply the subsequent layer within 48 hours. If more time elapses, consult your Master Builders Solutions representative.